ABSTRACT
A growing body of work suggests that the material properties of biomolecular condensates ensuing from liquid-liquid phase separation change with time. How this aging process is controlled and whether the condensates with distinct material properties can have different biological functions is currently unknown. Using Caenorhabditis elegans as a model, we show that MEC-2/stomatin undergoes a rigidity phase transition from fluid-like to solid-like condensates that facilitate transport and mechanotransduction, respectively. This switch is triggered by the interaction between the SH3 domain of UNC-89 (titin/obscurin) and MEC-2. We suggest that this rigidity phase transition has a physiological role in frequency-dependent force transmission in mechanosensitive neurons during body wall touch. Our data demonstrate a function for the liquid and solid phases of MEC-2/stomatin condensates in facilitating transport or mechanotransduction, and a previously unidentified role for titin homologues in neurons.
Subject(s)
Caenorhabditis elegans Proteins , Touch , Animals , Touch/physiology , Caenorhabditis elegans Proteins/genetics , Mechanoreceptors/physiology , Connectin , Mechanotransduction, Cellular/physiology , Caenorhabditis elegans/genetics , Neurons , Membrane Proteins/physiologyABSTRACT
Giant cell tumor (GCT) is a benign, locally aggressive neoplasm with little incidence at the carpal bone level. We present a case of pyramidal bone GCT that required open biopsy for diagnosis. As a definitive treatment, en bloc resection of the pyramidal bone and luno-capitate arthrodesis were performed to avoid frequent relapses of these neoplasms and ensure proper functionality of the anatomical segment.
